I can definitely see how small it is currently but I worry about some things in your set up. It doesn't appear that there will be much airflow through the cage which is very necessary for a veiled. Also the substrate, although it appears to be an organic soil of some sort, runs the risk of impaction for a chameleon, especially one that is as small as yours. I would consider putting that yemen in a 18 x 18 x 36 very soon. I didn't look to see if it was male or female but a female could keep that size cage for possibly the rest of its life.
I really like that enclosure.
Particularly the section of screen on the front to encourage airflow.
I am assuming the top is screen as well.
Depending on the ambient year-round temperatures in your home, you may or may not want to go with a screen enclosure when the animal graduates to a larger habitat.
Here is the information I have put together on the species: